Pylontech US5000 entladen mit hoher Leistung ohne daß die Loads am MP2 das erfordern

[homa]

@DavidOvNL

The documentation on S99 is severely lacking.

Appreciate your candor. I can second that as I am having the hardest time to sieve the details that are important in order understand the capabilities S99 firmware extends to vs. the regular firmware for the MP-II. I wish there would be more information or someone “experienced in using the S99 firmware” to be able to shed light.

@DavidOvNL

I noticed the sense point is drawn on the grid side of Q2 (is that the NA-relay of the CHPs?). So I would say that that means in case of a grid failure, the Victron cluster is disabled.

The “Netzanmeldung document” I did not update after extending the Cluster to 9 MP-II. And yes, the EM530 CTs sit ‘left’ of the “NA Protection”. This will ensure no current will show at the MP-II when the NA Protection is activated.

Note that

• the EM530 is powered after the Z4… so it will work when the NA Protection is active.
• the EM530 replaced the VM-3P75CT (also not updated in the drawing)
• the number of MP-II in the cluster on page 2 is also still on 6… means I did not update the drawing to reflect the ‘9’ MP-II

@DavidOvNL

How is the Victron installation told how much to supply? Grid setpoint?

The EM530 is configured as ‘GRID meter’ and uses the USB i/f on the Cerbo in order to establish communication between the EM530 and the CERBO via Modbus/TCP. This setup works well and tells the MP-II Cluster how much power can be directed to the batteries in order to prevent feed-in of excess power to the GRID. This also makes “CERBO monitoring of the CHPs” unnecessary.

@DavidOvNL

In the drawing there is also a control box (FRSE), I assume that is for EEG §9? How is that programmed into the Cerbo? Because is says 0-100% and that full rance control is not a standard feature on Victron.

In this case the EMS is monitoring the FRSE and in case it sets the PV Power to ‘zero’ the integration is to tell the CERBO to prevent DC PV feed-in. [>>Setup=>ESS=>Grid feed-in=>DC-coupled PV - feed-in excess<< to “OFF”]

@DavidOvNL

And the most important question I think; what was the purpose of the Victron installation?

Very simple. With two CHPs, an emergency Generator, 140kWh Battery, Fronius PV, Victron PV and the Grid…. the aim is to get to the lowest energy-cost-mix as well as run through the weekends with next to NO-GRID usage.

And to round it off… there is only 1 Fronius Inverter that is coupled on the AC-OUT-1… where as the rest of the PV is coupled via the MPPT RS450 set.

@DavidOvNL

What I mean is that you have multiple sources in the system which are all behind the EM530. Ideally you want these sources to cover the load and whats left can be put back on the grid. But one (actually two) of these sources is (are) supplying energy that in the eyes of the Cerbo ‘just appears out of thin air’.

My explanation for that is where I responded to your question about ‘GRID Set Point’.

@DavidOvNL

But this system should not have been built this way. A 135kVA system, when on-grid, should ALWAYS have the S99 firmware with external transfer switch.

This is exactly why I am trying to get my arms around the S99-System capabilities…. before I decide to change the existing setup to become a S99-System.

@DavidOvNL

What happens when the grid fails and the NA-Schütz that is built around the CHP’s trips? Do the CHP’s continue? Or do they stop?

When the GRID fails the NA Protection kicks in and separates the GRID from the location. The CHPs are still connected to the load-path at this time and supply whatever power they generate.